Remove race condition (in InstanceTypeProjects)

Soft delete all duplicate rows with the same (project_id, instance_type_id)
except one with the biggest value in `id` column.

Create UC on columns (project_id, instance_type_id, deleted)

Add tests for migration

Fix instance_type_access_add method
	Replace Select then Insert -> Try to Insert.

blueprint db-enforce-unique-keys

Change-Id: Id70509337e78f3bf778501f2c77aa03263580ef0
Add missing tests for instance_type_extra_specs_* methods

There was no tests in test_db_api for instance_type_extra_specs_*
methods.

Add tests to ensure that all works.

blueprint db-api-tests

Change-Id: Ie88aa776574c5ddf37a1adcf7cc2c9e70c6eb810
Merge "Remove race condition (in InstanceTypeProjects)"
Merge "Add missing tests for instance_type_extra_specs_* methods"
Merge remote-tracking branch 'm_src_repo/citrix-fixes' into build-temp